Research On Reliability And State Evaluation Decision Of Relay Protection Equipment

Relay protection is to detect faults or abnormal conditions in the power system to ensure the normal and reliable operation of the power system.With the development of national economic productivity,the construction of power grids continues to deepen,and the role of relay protection equipment is particularly important.Under normal circumstances,there are two methods for reliability analysis of relay protection.One is based on the reliability maintenance of relay protection,and the maintenance strategy is continuously updated to formulate the maintenance sequence.The other is based on the status information of the collection equipment.State assessment,so as to arrange maintenance according to local conditions,both methods are aimed at relay safety and normal operation.Therefore,this paper conducts relay protection reliability research from the above two aspects to ensure the reliable operation of the power system.This paper focuses on the reliability analysis and state assessment of relay protection,mainly to carry out the following work:First of all,this paper introduces the relevant research background and research significance,expounds the importance of reliability analysis and state assessment for relay protection,and discusses some problems in the evaluation of relay protection status.Then,systematically introduce the reliability index and reliability factor,and sort out the common methods of relay protection reliability and state assessment,and combine the problems of relay protection reliability research and the basis of state assessment method to determine the basis of this paper.Method of relay protection analysis.Secondly,using the failure mode and effect analysis(FMEA)combined with function and structure,on the basis of comprehensive consideration of relay protection function,complete the FMEA table for relay protection and determine the main relay protection.Failure mode.Considering the uncertainty of failure probability and logical relationship,based on the traditional fault tree,the TS fuzzy model is introduced,and the TS model rule table based on expert opinion is established to carry out the reliability analysis of TS fuzzy fault tree relay protection and calculate the fuzzy of system fault.Probability,TS probability importance and TS key importance,and verify the validity and reliability of the evaluation method through examples.Finally,the rough set theory and cloud theory are applied to the evaluation of relay protection status.The state evaluation system of relay protection is established.Considering the possibility that the rough set determines the weight is zero,the improved rough set theory is proposed as the theoretical method to determine the weight coefficient of the relay protection state quantity to ensure the weight and actual situation of the relay protection index.Compatible.Due to the uncertainty and randomness of relay protection,the cloud theory is adopted for this purpose,and the correlation degree of each indicator of relay protection is determined by cloud generator,and DS evidence theory is introduced to evaluate the overall index of relay protection,which is the status of relay protection status.The division provides a new direction of thinking.